A. Field of the Invention
The present invention relates to the field of tissue adhesion treatment and prevention, and more particularly to a method for reducing the incidence of adhesions through the application of low frequency sound to inflamed body tissues and organs.
B. Adhesion Prevention and Treatment Techniques
Adhesions are a type of scar tissue which may undesirably form between inflamed or traumatized portions of an organ and adjacent body tissues. Almost any inflamed tissue can form adhesions to adjacent tissue if these tissues are left in contact over time. It is theorized that within several minutes light adhesions form, and are most frequently replaced after several days by heavy permanent adhesions.
It has been estimated that more than 98% of all patients undergoing abdominal surgery develop unwanted internal adhesions. Such adhesions also complicate pelvic, thoracic, articular and neuro surgery. Adhesions are the greatest cause of intestinal obstruction and strangulation. They are also the greatest cause of infertility in females. Once adhesions have formed, medical complications from those adhesions may develop at any point in a patient's lifetime.
Although the severity of adhesions has been reduced somewhat by enlighted surgical techniques, the incidence of adhesions following surgery is still quite high. In an article entitled "Cause of Abdominal Adhesions in Cases of Intestinal Obstructions", by L. E. Raf, Acta Chir. Scand., 1969, 135:73, Raf reported that, of 2,295 records of patients with small bowel obstructions, 64% were secondary to intra-abdominal adhesions. As causative factors, previous appendectomy and gynecologic procedures were noted in 86%, while in 18% there was a history of infections. Intestinal obstrutions are lethal in 27% of patients in the sixth decade and 54% of those patients who are more than 70 years old. See "Intestinal Obstruction: Ten Years Experience", J. C. Giuffre, Dis. Colon Rectum, 1972, 15:426.
Adhesion etiologic factors involve inflammation which may be secondary to foreign bodies, infections, trauma, radiation, or, most potently, ischemic tissue of any sort. Deperitonealized surfaces are not a significant cause of adhesions; in fact, there is evidence suggesting that the suture material used in reperitonealization can cause adhesions. Adhesions of fibrin from blood clotting factors may be present two hours or less after an operation. Organization to fibrous adhesions comprising collagen occurs most frequently within two weeks. The latter plays a valuable role in supplying new vasculature, limiting infection and providing support for parenchymal discontinuities. The post-operative incidence of adhesions is increased in infants, but there is no preference for age or sex in adults.
It is not known whether the vast majority of adhesions are indeed harmless, as is sometimes suggested. Adhesions are often associated with abdominal pain and dyspareunia. The results of two studies by Triotskii implicate adhesions as the earliest route for metastatic spread of carcinoma within the abdomen. See Triotskii, R. A., "Role of Adhesions in Metastasis of Cancer in Peritoneal Cavity Organs", Vestn. Akad. Med. Nauk., SSSR, 1967, 22:55; and Trotskii, R. A.,; "The Spread of Cancer in the Large Instestine in Adhesions under Experimental Conditions", Eksp. Khir anesteziol, 1970, 15:44.
To date, many techniques have been suggested as a prophylaxis or treatment for adhesion formation. Such methods have generally involved either surgical intervention, drug administration, or mechanical manipulation or separation of the inflamed surfaces. To date, such procedures have attained only limited success due to the side effects attendant to such procedures and the inconsistent results achieved thereby.
To date, the preferred prophylaxis entails sterile technique antibiotics when appropriate, minimizing tissue damage and operating time, and protection from foreign substances. In "The Cause and Prevention of Postoperative Intraperitoneal Adhesions", by H. Ellis, Surg. Gynecol. Obstet., 1971, 133:497; attempts at aggressive prophylaxis are summarized. Prevention of fibrin deposition by anticoagulants has been abandoned because of hemmorrhage. Removal of fibrin polymers by lavage and enzyme administration has proved to be inconsistent or ineffective. Furthermore, Nissel and Larrson have reported that fibrin is neither necessary nor sufficient for adhesion formation. See Nissel and Larrson, "The Role of Blood and Fibrinogen in Development of Intra-Peritoneal Adhesion in Rats", Fertil. Steril., 1978, 30:470. Separation of serosal surfaces with oxygen, saline solution, oils or macromolecular solutions have been associated with increased adhesion formations. Similar results have occurred when traumatized surfaces have been covered with gold foil, amniotic membranes or omental grafts. Induced peristalsis with enemas, cathartics, heat or autonomic drugs has been dangerously difficult to control and associated with numerous ill side-effects. Corticotropin, steriods and other anti-inflammatory agents have shown prolonged healing time, ulcer generation and abscess formation without consistent prophylaxis of adhesions. Plication of the small intestine as recommended by Noble is an extensive procedure; it is reserved for those patients with multiple reformations. Results are again inconsistent. See T. B. Noble, "Plication of the Small Intestine as Prophylaxis Against Adhesions", Am. J. Surg., 1937, 35:41. See also N. D. Wilson, "Complications of the Noble Procedure", Am. J. Surg., 1964, 108:264. The removal of adhesions surgically almost certainly leads to a greater reformation of adhesions in the treated tissue region.
For organ surfaces to become adherent during an inflammatory epsiode, they must be in contact long enough for the polymerization of the fibrin and collagen fibers between them. In the case of abdominal surgery, the normal peristaltic motion of the bowels ceases for a time roughly proportional to the severity of the operation. Generally, in patients whose peristalsis returns rapidly, the number of adhesions is less.
Early researchers attempted to replace lost peristaltic motion by several methods. One method was to constantly change the position of the patients in bed. Another was to use large suction cups on the abdomen to alternatively pull and push the abdominal wall. Another method used forced feedings and enemas containing iron filings followed by the periodic movement of a strong magnet over the patient's abdomen. These methods were incompatible with the comfort and well being of the postoperative patients.
Thus, as seen from the above, considerable attention has been given to the problem of adhesion formation, and its prevention, however, a simple, safe technique which is effective to prevent adhesions has heretofore been unknown to the art.